It is old, as shown in U.S. Pat. No. 3,855,587, to utilize a battery to power a lamp changer control circuit for rotating a turret having a plurality of lamps when one of the lamps burns out to place a new lamp in an operating position, such as in a navigational light.
In installations where alternating current is available, it is desirable to use an alternating current power source for powering a lampchanger control circuit thereby overcoming the problem of the short life of a battery powered supply. However, in utilizing an alternating power source which provides pulsed signals to flash a lamp, various problems in recognition and actuation are encountered since the pulsed signal may be as short as 0.3 seconds. In addition ac power peaks adversely affect circuit operations.
The present invention is directed to various improvements in an alternating current lampchanger control circuit which receives pulsed alternating current signals for lighting one of the lamps in a rotatable turret and includes an alternating current motor for rotating the turret when a lamp burns out to place a new lamp in position.